2009-04-30

With a release date of May 1, OpenBSD 4.5 is probably going to be hitting the mirrors later today -- maybe late tonight.

Notable features and enhancements:* Enhanced support for the sparc64 platform* Support for more hardware monitoring sensors* Lots of new or improved drivers for miscellaneous hardware* Reliability and security improvements from 4.4, which was fraught with a couple of critical issues.

Thanks to Venture37, I've already got my hot little paws on 4.5; I didn't get to pre-order it. I plan on upgrading my main workstation to 4.5 over the weekend, but for the time being, this looks like a release worth upgrading to!

If you're not familiar with OpenBSD, it uses a "text-adventure" style installation script with a couple of very straightforward options. The only tricky part is partitioning and formatting the disk for installation. The Installation Guide can help you set up the disks.

Once installed, OpenBSD is "secure by default" without any remote services running other than the ones you specify. The only ones you can enable during installation are ntp and ssh (but they default to disabled).

OpenBSD's minimalist nature means that you're left with a powerful but svelte platform upon which to build to suit your needs: whether that's a workstation, firewall/router or an Apache/MySQL/PHP (OAMP) web-hosting environment. The installation media comes with apache, Xenocara (which includes Xorg), GCC, perl, SuhosinPHP and a host of other open-source components, most of which have been audited, patched and hardened by the OpenBSD dev team.

2009-04-29

This is intended to be a supplementary information resource on cryptographic best practices. In this article I will cover some cryptographic algorithms with known flaws and some alternatives.

=== ToC =============

1. Introduction

2. Known insecure encryption technologies

3. Alternatives

4. Informative resources

====================

1. Introduction

Security is not the black box on your desktop or network. It it isn't a graphic you put on your website saying that the site is secure because you have a firewall. Security is the constant dialog between you and the other people in your organization on how to best secure the information which you have been entrusted with.

To that end I would like to bring up some technologies which we should avoid or migrate away from at our earliest opportunity.

2. Known insecure encryption technologies.

DES - DES has been broken for quite a while.

MD5

SHA1

DES stands for Digital Encryption Standard, it was developed by IBM in 1972. Originally the team at IBM was said to have specified a 128 bit algorithm but was later asked by the NSA to reduce it to 64bit and later 56. This is refuted by government probes, then the insecurity was verified by cryptanalysis and later interviews with the people involved in the project and in de-classified documents.

MD5 is a hashing algorithm designed by Professor Ronald Rivest of MIT. There was research which theorized collisions in the algorithm in 1993, more collisions in 1996 and finally an algorithm was created to generate collisions in 2005 using a large cluster and in 2006 the algorithm was perfected only requiring a single computer.

The SHA cryptographic functions were written by the NSA in 1992. In 2005 flaws were found in the SHA-1 algorithm, although these flaws are yet to be exploited it was decided to move on to a different algorithm.

Things that were never a good idea to begin with:

Character replacement ex. ROT13, Caesar Cipher

XOR encryption against a trivial key

base64 encoding (or any other encoding)

Character replacement, encoding and XOR are trivial to decrypt/decode. In the case of encoding or replacement, these are easily detected because the structure of the message itself isn't changed. XOR is computationally simple so brute forcing, frequency analysis and other methods can be used to decipher it. Using XOR against a very complex non-repeating one-time pad can offer quite a bit of security as long as strict protocol is followed in handling cleartext and the pad itself.

3. AlternativesDES users should consider using AES, preferably one of the versions with larger key sizes 256 or 512. MD5 and SHA1 users should consider using the SHA-2 algorithm which are considered to be safe for now. There is an on-going contest to decide what algorithm to use for the new SHA-3 standard.

Many SSL certificates are signed using a MD5 algorithm. This creates the possibility of forging ssl certificates. In addition there was a bad patch to the OpenSSH package in Debian Linux in 2008 which made certificates generated by the affected server insecure. There is a firefox extension which will warn you if the certificate is vulnerable.

2009-04-28

Just a reminder for the Kansas City crew: We've heard some rumblings that the Independence 2600 meeting seems to be a wash. I know it's a bit of a haul for some people in this sprawling metroplex, but KC 2600 is alive and well at Oak Park Mall in Overland Park, KS.

Official start time is 5:00 PM but sometimes we run a little late. You can usually find us near Street Corner News in the food court. There's a large pillar (with power outlets!) so keep your eyes peeled for geeks with excessive amounts of gadgets.

The weather forecast for Friday looks pretty gloomy. Not sure what we're food-ing after the meeting, but attendees are invited to my place afterward for grub, suds, more discussion and geekery.

2009-04-27

Fact: More people will die of heart disease and traffic accidents today than have died by Swine Flu in the past week.

Fact: People will drive to and from work today, probably stuffing their faces with McGriddle sandwiches, breakfast burritos or grease-burgers while living in fear of getting sick by the media-hyped pandemic.

Fact: Some of those scared people will have a heart attack or get creamed by a drunk driver in the next few days.

Intelligent life. It's a scarcity on our own planet, so we look beyond our atmosphere, hoping to find something, somewhere out there in the vastness of space that has more than two or three brain cells to rub together.

Have you ever seen the kinds of things we've sent into space for others to find and make sense of? I've often myself wondered what our own scientists, hackers, and problem-solvers would make of these messages.

In 1972 and 1973, Pioneer 10 and 11 were respectively sent off into space. Both were labeled with a gold-plated aluminum-alloy plaque engraved with information about humans, Earth and our solar system. Warning: If you zoom in on the image, it includes drawn nude human anatomy.

On November 16, 1974, Scientists at the Arecibo Observatory in Puerto Rico blasted 1,679 bits (not bytes!) into the sky at 1 bit per second, aiming their transmitter at Globular Cluster M13, some 25,000 light years away. How much information can be contained in 1,679 bits? What would you do with it? Would you even know where to begin? It's not divisible by 8, so it isn't using "bytes" in the traditional way you would expect. Remember, this is 1974 and the message is intended to be received and decoded by intelligent life.

The answer is interesting, and the binary stream above was crafted by some of 1974's most brilliant minds.

In 1977, two identical Voyager Golden Records were sent into space aboard Voyager 1 and 2. The record itself contained several recordings including an audio representation of captured brain waves. It was pressed in copper and plated with gold, but was technologically identical to vinyl phonograph records of the era, and I believe it would likely play on any regular phonograph. The record itself was contained in a cover (shown below, click to zoom) that contained similar information to the Pioneer Plaque.

Would an alien civilization understand what to do with any of these? What would Earth's own hackers and scientists do with information like this if we found it? Things like this fascinate me, and the 1970s were certainly an exciting time for technology and communications, which includes the space program.

The Apollo 13 mission itself (April 11-17, 1970) is proof of the kinds of things that hackers can do. While the mission was a failure, geniuses hard at work within NASA were busy finding ways to force equipment to do things that simply "couldn't be done" in order to bring the crew home safely. I don't know if it was actually spoken in real life, but in the movie Apollo 13, Flight Director Krantz tells off an engineer who is concerned about equipment being used unconventionally: "I don't care about what anything was DESIGNED to do, I care about what it CAN do." If that's not the hacker spirit, I don't know what is!

In short: the answer is "well, you're hosed." But GPG has some other features built-in to help you out. You just need to be prepared. That usually means having a revocation certificate ready to use. I'll cover that in a moment.

If you have lost your secret key (the secret keyring file itself) for any reason, for all intents and purposes you cannot ever decrypt anything that was encrypted with your public key ever again. The secret key is almost assuredly much, much more complex than the password or passphrase that you chose to protect it. As MC Frontalot would say: "you can't hide secrets from the future with math." so when petaflop computing power comes to the desktop, you may be able to crack it in a matter of months. Until then, your data is gone. This includes any new communication sent to you from others who have your public key.

Obviously, if people are sending you encrypted data and you have no way to decrypt it, that's A Bad Thing™.

If you have simply forgotten your passphrase, and it's a simple one that's 8 characters or less, alpha-numeric with upper/lowercase and no keyboard symbols, you may be able to brute-force the password that is protecting the key. That's way beyond the scope of this post.

Enter: Key RevocationRevoking your public key is a quick way to advertise that the key should no longer be used. This can be for many reasons. The most obvious is if you feel your secret key has been compromised. In the event that your workstation got rootkitted, your backups were stolen, or you errenously left your secret key somewhere that it could have been accessed by someone else, you can't rely on the passphrase itself to maintain absolute secrecy of your data. Remember: passphrases can be cracked much easier than the unprotected secret key itself.

When to generate a revocation certificate:I usually generate one soon after generating my keypair, which states "I have lost the secret key" or something of that nature. If you lose the secret key or forget the password to it, it's too late to generate the revocation certificate. You need both the secret key (and thus its password) to do this.

If you fear that the key has been compromised, you should generate one at that time which states the nature of the compromise.

To generate a revocation certificate, issue "gpg --gen-revoke [keyID]" and follow the prompts.

$gpg --gen-revoke 19A473C7

sec 1024D/19A473C7 2009-04-25 Test! (This one is getting revoked!)

Create a revocation certificate for this key? (y/N)yPlease select the reason for the revocation: 0 = No reason specified 1 = Key has been compromised 2 = Key is superseded 3 = Key is no longer used Q = Cancel(Probably you want to select 1 here)Your decision?3Enter an optional description; end it with an empty line:>I'm revoking this on purpose>Reason for revocation: Key is no longer usedI'm revoking this on purposeIs this okay? (y/N)y

You need a passphrase to unlock the secret key foruser: "Test! (This one is getting revoked!) "1024-bit DSA key, ID 19A473C7, created 2009-04-25

ASCII armored output forced.Revocation certificate created.

Please move it to a medium which you can hide away; if Mallory getsaccess to this certificate he can use it to make your key unusable.It is smart to print this certificate and store it away, just in caseyour media become unreadable. But have some caution: The print system ofyour machine might store the data and make it available to others!-----BEGIN PGP PUBLIC KEY BLOCK-----Version: GnuPG v1.4.9 (OpenBSD)Comment: A revocation certificate should follow

This key, if it falls into the wrong hands, can be used by anyone to revoke your public key! Make sure to keep it safe. Back it up onto long-term storage that is reliable, or even print it out. It's relatively short, so it won't be too hard to type it in manually.

To use the revocation cert, simply import your public key (if it's not already in your keychain) and import the revocation cert. This will merge it with your public key and notify GPG that it's no longer valid. Then, if you have exported your public key to a keyserver, export it again as shown in part 1.

You should also contact those who may send you communication and let them know to refresh your key from the keyserver. Until they do so, their installation of GPG (or other OpenPGP compliant software) will not know your public key has been revoked.

Of course, it's best to avoid the need to revoke certificates in the first place!

Keep your secret key in a safe place, such as on your workstation, not a file-server or a shared host.

Keep UNIX permissions at 600 (rw- --- ---) or otherwise make sure your account is the only one that can access the keyrings and/or any exported secret keys.

Back up your keys to long-term media (CD-RW is usually fine) and keep it in a place that's safe from attackers and environmental harm (a cool, dark, dry place like a fire safe).

For crying out loud, remember your passphrases without making them short and/or easy to guess. Example: use a favorite quote or passage written in l33t. Preferably a passage that few people know you like. Using your email signature line? Bad idea.

I might be preaching to the choir here a little bit, but perhaps you need a quick reminder to back up your personal workstations as well as your enterprise data.

After two and a half years of what I can only describe as abuse, my MacBook's hard drive gave up the ghost last night. This thing has traveled over 5,000 miles with me on my bicycle in my panniers, been slung hither to yon on buses, subways, planes and trains. Until recently, it was even my primary workstation at home.

It came with little surprise: my hard drive died mostly due to shock. Not one brute-force blow, by any means. It was just its time. As I sit here letting Time Machine restore my old stuff, I can say I'm thankful that I was at least somewhat diligent about backups. I probably only lost a few photographs that were on my hard drive for the past few days, and some of those got uploaded to Flickr anyway. The only lump in my throat was from having to explain to my wife why I'll need to lay out a Benjamin for a 320GB SATA drive this coming paycheck. It's amazing how much laptop storage you can get for $100. It's too bad I have to do this now, because it looks like the 500GB drives are going to be there soon.

You can read all kinds of reviews about Time Machine as a bare-metal restore tool as well as recovering from accidental data removal. I won't dwell on that here. All I can say is that when the time came, I wasn't sweating any bullets about my lost data. I can simply fork over some cash next week, and everything will be back the way I left it.

However you get your backups done, consider this a reminder to remain diligent. You never know when you'll need to restore, and the backup you made 8 months ago, while better than nothing, probably will leave you with a bit of regret.

Amateur licenses are inexpensive to get and they require only a basic understanding of radio waves, Allotted FCC Frequencies for amateur use, basic electronic theory and FCC rules and regulations in regards to Ham radio.

The best way to find out about official testing for a Technician License will be through either a local radio club, a local or regional ham radio equipment store or... the Internet.

The test is fairly simple, under 50 questions and it covers mostly opperating procedures, FCC regulations, basic electronics and basic radio theory. They throw in some minutia questions covering basic electronics, radio theory and ham spectrum information just to make things interesting.

Once you have passed the test, they will send your details to the FCC who will then log your information into their national database and assign you a sequential amateur call sign. You can even create a semi-custom call sign for an additional fee.Once you are logged into the national database you may then transmit on the amateur radio frequencies.

Gotchas:1. You may not use codes or encrypted transmissions.2. Only licensed radio operators may use the ham radio bands. There are specific regarding what may be transmitted and by/from and to.3. Every radio transmission you make must have your call sign associated with it.4. If you can't say that on television, you cant say that on the radio. (no cursing)5. If you get caught breaking the rules, you could loose your license, go to jail and or get fined.6. Certain frequencies are restricted to certain types of communication, for instance certain bands are limited to Morse code only, while others you can use, voice, packet radio or TV.

2 . Common HAM radio ActivitiesAmateur radio operators exist to innovate and expand the field of radio electronics, promote international communication and good will and provide emergency communications when needed.

There are regional, national and international radio organizations who provide resources for management of the radio spectrum and emergency communication services. A common activity to the emergency communications mission is creating an emergency "jump pack" which contains all of the necessities to create a mobile communications system. Many people have modified their vehicles to be able to serve this purpose. Others have mobile towers and camping gear to create a command center of sorts when the need arrives. Common activities amongst these groups are training exercises where radio transmissions sources are traced to their source. This is called a fox hunt.

Other activities HAM operators do is to access gateway or relay resources. A gateway could be a packet radio node which could connect a ham operator to the Internet (albeit very slowly (9.6 kbps max). There are also telephone relays which allow a HAM operator to connect to the phone network to make an out going call.

A common activity of some HAMs is to use an Internet gateway to send GPS information automatically to a tracking website, like bright kite.

You may also transmit video over radio.

The ionosphere is a wonderful thing, radio can bounce off of the ionosphere and reach whole other continents. There are no restrictions on who you can talk to, provided both governments are not at a state of war or some other political barrier exists.

Now here is the tricky part, A HAM operator must allow the FCC to inspect their radio upon request. SO if one were to modify the radio to transmit or receive on channels which the operator is not licensed for they can do bad things to you. However in an emergency transmitting on a restricted (emergency services frequencies for instance) is a forgivable offense. So it seems that there is a kind of unofficial grey area in regards to radio modification, a kind of "if you do this there had better be a darn good reason" kind of thing.

I've been on the "good enough" bandwagon for at least 5 years. It's been long possible to "just barely keep up" with tech and stay in a decent budget. I buy stuff that's about 3 years or more old (unless something awesome drops off the back of a truck...) and it usually lasts me 6 months to a year, or more. And my purchase price is always 5-25% of the original price. Get a barely 3 year old IBM desktop, once $1200 for $30? Even with upgrades and replacement parts it's a steal. It's also all modern tech, with SATA, PCIe, DDR2 RAM, etc. so upgrades are cheap and plentiful. "Good enough" is often "not new" too... and that will be a push during the recession that will force manuf.s to keep low prices.

2009-04-17

Introduction
Although I'm a fan of TrueCrypt for full-disk encryption and folder encryption I still rely on Gnu Privacy Guard for some of my needs. GnuPG is an Open-Source encryption tool that adheres to the OpenPGP standard. That means that this should also work on most other CLI OpenPGP-compatible packages as well. It's lightweight, cross-platform, and there are front ends that make it relatively easy to use. It can output ASCII that's easy to send in an e-mail or copy/paste into a document.

Compiling and installing GnuPG is beyond the scope of this article. That said, it's usually easy to install without compiling it, since GnuPG is available in many package repositories for Linux, BSD and OS X. Try installing gnupg, gpg or GnuPG to see if it shows up in the repository. On OpenBSD, it's as simple as running "sudo pkg_add -r gnupg". The windows package is available through the GnuPG website (linked above).

Today, I'm going to focus only on the command-line key-management features. They work the same on all platforms.Quick-Ref
Look, I know some of you guys probably don't need to see the whole screen-shot walk-through for this. If you just want to tinker around or you already have some experience with PGP-Like tools and just want to know how to use a keyserver, sign other peoples' keys and the like, here are a few helpful commands.

Generating your first key
If you've never used GnuPG before, you will have to generate a key pair. This key pair includes a public key and a secret key. The public key can be shared, and is used by anyone who wishes to send you something encrypted. Using your password-protected secret key, you can decrypt what is sent to you. This is called asymmetric crypto because a different key is used for encryption and decryption.

To generate a new key pair, use gpg --gen-key and then follow the prompts.

You can export your key to an ascii file with the following command. Note, we use the hex key ID for our public key as shown above. By default, GPG exports in a binary format. the "-a" option enables "ASCII Armor" mode, which is similar to uuencode or base64 in that it takes up more characters but is more human-readable.

You can upload the public key to your website and link to it. You can attach it in email, or you can just copy-and-paste it since it's ASCII Armored.

Using the --export-secret-keys option, you can similarly export your secret key. Make sure to use the -a option if you wish to have it in a text file format. AND BE SURE TO KEEP THIS KEY SAFE. If your secret key is compromised, the password protecting it is a relatively small obstacle compared to the key itself.

You can also export your public key to a keyserver. This is a public repository that lets people search for and request GPG keys for people they know. Many of these keyservers are synchronized with one another. Read about Synchronizing Key Servers here. Two SKS search links:

You can upload anyone's public key to a keyserver, but you probably shouldn't without their permission. The exception is if you're going to sign someone else's key that's already on a keyserver. I'll cover that later.

The email addresses, names, and any other information that's part of the key will be forever stored in plain-text and indexed. This could open the email address up to being spammed, or could reveal more personal information than you'd liked. I'm just saying be careful with what you put in your key. The metadata may become public.

Importing keys

You can import keys a few different ways. The most basic is to download the key or paste and save the key as a text or ascii file. Then you import the key with --import [filename]

You can import both public and secret keys this way. GPG will auto-detect what kind of key you import.

Hopefully, Phoneboy does not mind me using his key as an example. He links to it from his blog (which is a good read if you're into telecom and/or security stuff)

You can also import the key from a keyserver, much like the export we described above. You do need to actually go to the keyserver to find the Hex KeyID though, or A856F98C in this example, which is Packet Storm Security's key.

The beautiful thing about GnuPG (and other PGP-based solutions) is that you can create a "web of trust" with friends and colleagues using a keyserver. Basically, you have other GnuPG users you know sign your key. This means that they have certified that a public key belongs to you. With enough signatures on your public key, this makes it more difficult for an impostor to masquerade as you. The GNU Privacy Handbook's section on Building Your Web Of Trust explains it in more detail.

In the examples I've shown importing keys, you can see some information about depth, trust, signed, and the like. I won't get too deep into this, just enough to get you started because the above link really is a good read.

If someone sends you a public key, you can't 100% trust that it is theirs, especially if it's someone you do not know well or in person. It may belong to an imposter who has registered a convincing email address and has created their own key. Communication that you encrypt for the person you believe you're talking to could actually fall into unintended hands. It is for this reason that key signatures come in handy.

Fingerprints are cryptographic hashes that can be used to authenticate the key, but are short enough that one can scrawl them onto a napkin or the back of a business card. If you have verified the fingerprint of a person's key while you're there in person, you can verify that fingerprint against the key when you receive the key from them (or from a key server) later on. Once you verify that the key is authentic, you can "sign" it and then re-upload it to the keyserver. This means that you have personally vouched for the key's authenticity. If enough people vouch for one another's keys, the Web Of Trust is formed. Any person who may not know someone well enough to trust the key can see that several people vouch for the authenticity of the key. Perhaps one of the signers is even a mutual friend.

Key Signing
Signing is pretty easy:

You import a key from a keyserver (see example above)

You sign the key: gpg --sign-key [KeyID] (you'll be prompted for your passphrase)

You export the key back to the keyserver (see example above)

Key-Signing PartiesThrowing a Key-Signing party is a geeky way to vastly increase the size of your Web Of Trust and maybe interest others in encryption.

If you're going to try to get some people together to sign one another's keys (say, your local hackerspace, the 2600 participants, or your colleagues in the office), you should have a few things in place:

Every participant's public key should be uploaded to an agreed-upon keyserver or synchronizing keyserver network.

Every participant should have their hex KeyID, Name/Email and public key fingerprint written down or printed out. It's easier if participants print out several copies per page of paper (as shown in the photo) and cut them into strips to hand out to other participants.

All the participants should know one another and be able to verify each other's identity. You don't need to flash Drivers' Licenses and compare them to the real name on the key, but it wouldn't hurt.

My Keysigning Party Paper just repeats the following block of text as produced by gpg --fingerprint [keyID]:

Participants basically make their rounds, gathering key information from every other person in the group. Then, everyone imports everyone else's key from the keyserver and verifies that the fingerprints and e-mail addresses match the ones they were given in person. After that, sign all the keys, and export the keys back to the keyserver.

2009-04-08

Actually, there are locks built into the doors of this roadside telecom cabinet (and they are locked), but these two chintzy padlocks have been unlocked like this for the past few days. I'm not sure what the deal is here, but I chuckle every time I pass it.

2009-04-01

Well, it's April 1st, and the Internet (and its lies stupid pranks) are still alive and well. The hype of Conficker causing some kind of Internet-crashing, world-dominating clustercoitus have played out the way the real security experts (as opposed to so-called 'Computer Experts') had expected.

In case you missed it, the reason that experts weren't freaking out about Conficker are because some very smart virus researchers had already picked apart the Conficker.C variant and determined what it's going to do today. It's really nothing serious. Check out the F-Secure Conficker.C Q&A and SRI's more detailed Analysis of Conficker.C.

Of course, just because the world won't die by Conficker's hands doesn't mean it's okay to be lax on your security. You should still:

In the hacking culture, exploiting buffer overflow vulnerabilities was known as "Smashing The Stack", as stack-based overflow exploits were (and likely still are) the most common buffer overflow vulnerability and among the easiest to exploit.

Kevin's article and the accompanying animation reminded me of a piece of work that is both antique (as far as computer history is concerned) and relevant. Phrack 49 was published in 1996, and it included an article by Elias Levy (under the handle of Aleph One) entitled "Smashing The Stack For Fun And Profit"

It's practically required reading for people dealing with application security; It's just as useful for developers as it is for penetration testers and security researchers. Seriously, go give it a read. It's a long one. All the while, keep in mind that it was released nearly 13 years ago. That even puts my own work into perspective. Phrack 49 was released just as I was myself trying to rally the writers who put together the very first bits of content that got HiR off the ground in its original eZine format.

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About HiR

HiR is what happens when 1990s-era e-Zine writers decide to form a blog. Most of us hail from the Great Plains region of the United States.

Ax0n, HiR founder and editor-in-chief is an information security specialist currently working in the luxury goods industry.

Asmodian X joined HiR in December 1997 and currently works as a web developer and SysAdmin in the education industry.

Frogman has been on board since May 1998 and has many technical passions. When not experimenting with obscure hardware, he can be found leaping from one rooftop to the next, making the world his office.

TMiB has also been helping since 1998. Also our resident Physicist and go-to guy for xkcd jokes we don't get, The Man in Black currently works in the Internet industry in an east-coast data center.